As it is known by specialists on the art, reciprocating compressors comprise fundamental electromechanical equipment composed by an electrical engine, a compression mechanism and at least one electronic central, all this equipment being disposed inside a hermetic casing. Generally, the compression mechanism is basically integrated by a piston, by a cylinder and by a head.
The piston is somehow, mechanically linked to the electrical engine, wherein this way of linking is capable of transform the rotational movement of electrical engine in linear reciprocating movement of the piston. The cylinder comprises the environment wherein the piston is reciprocated. The head comprises the mechanical set that controls the work fluid flow.
Broadly, a reciprocating compressor head comprises at least an exhaust port and at least one suction port, as well as at least one exhaust valve and a suction valve. As it is known, the main function of the valves relates to fluid flow control which flows in one of the ports, thus, the suction valve controls the fluid flow which is admitted inside the cylinder thought the suction port, and the exhaust valve controls the fluid flow that exits the cylinder through the exhaust port. Thus, it is noted that efficiency of a reciprocating compressor is, among other features, regulated by correct functioning of the valves from compression mechanism head.
Different positioning check or improper reciprocating compressor valve opening systems and/or methods are well known by the specialists on the art. Generally, such systems and/or methods have the aim check if the valves are actuating as expected, this is, if the valves seal their ports when this seal is necessary, or if the valves unblock its ports when the fluid flow is necessary.
Obviously, the specific features of the already known systems and/or methods for checking integrity of the reciprocating compressor valve are related to valves constructiveness whose integrity is desired to be checked. In case of reed valves (metallic blades disposed over or under a port, in way to seal or unblock it according to the fluid flow way), for example, and as described in document BR1020130035599, filed on Feb. 15, 2013 by the Applicant, is provided a system and method of checking the reciprocating compressor valve operational state. The system and method described on said document BR1020130035599 need to use at least one inductive component, at least one sensor and at least one data processing core. Thus, the inductive component, being is capable of induce electromagnetic field whose intensity ranges according to the relative vicinity to metallic valve, is capable of stimulating, proportionally and stepwise, the sensor, being the signal acquired by the sensor directly proportional to the valve opening or closure. Although the system and method described on said document BR1020130035599 are functional, it is noted that is necessary use specific additional elements that can increase the production cost of the reciprocating compressor.
On the other hand, document JP04123893, filed on Oct. 15, 2002, describes a screw compressor that foresee automated interruption of electrical current of its electrical engine from checking determined movement of one of its valves, wherein movement information (or instant positioning) of said valve is acquires by means of electrical current variation of the engine. Generally, the system described on this document has the function to turn off the engine of the compressor in fault mode generated by the valve.
Furthermore, document JP04175912, filed on Feb. 17, 2003, a control method of car air-conditioning system compressor capable of check possible abnormalities on exhaust cycles through power amplitude against electromotive found on compressor engine. Specially, power variation against electromotive is seen by means of monitoring the tension terminal of the responsible circuit by engine electrical power (frequency inverter) during engine shutdown, being said power against electromotive generated by abnormalities on the compressor exhaust valve. It is based on this scenario that the present invention arises.